Labs

Laser printer megatest - Colour laser printers

In this month's Labs, we test a broad selection of laser printers designed for a wide range of budgets and roles. As a result, our contenders aren't all directly comparable: monochrome desktop printers simply don't compete with fully featured colour business devices - on price or features - and it would be meaningless to compare them.

Mono, colour and business

This month's Labs is therefore divided into three groups: monochrome, colour and business, and printers are compared only within their categories. For a detailed breakdown of the scores within each category, take a look at the analysis on p92, p98 and p106.

In calculating our scores, we consider the typical usage model for each category. For example, monochrome lasers are commonly bought for individual and small-office use, so size and upfront affordability are important in this category. Such a printer will also spend a lot of its time in standby mode, so we're interested in warm-up times and idle power consumption, too.

A colour laser is more likely to serve a whole office, printing many thousands of pages during its lifetime: ongoing maintenance costs thus become a greater concern, as do features such as network connectivity, remote management and paper handling. And, since you're paying more for colour, we take a close look at the quality of each printer's graphical output.

Fully fledged business printers, meanwhile, command premium purchase prices on the strength of their professional credentials, so from these units we expect fast, high-quality output, low running costs, remote manageability and a good range of expansion options.

Standard tests

While our assessments are category specific, they're based partly on a standard series of print tests, to which we subject every printer to determine its speed and quality.

For our first test, we time how long each printer takes to output 50 copies of the ISO single-page business letter. The document features a small red graphic, but we print it in monochrome even on the colour printers to ensure a level playing field for this test.

We then set the colour printers printing ten copies of a slightly more complicated five-page ISO colour newsletter, a test that includes black text on a variety of coloured backgrounds, plus coloured graphs and photos. This second 50-page test exposes the speed difference between printing colour and monochrome documents.

Next, we print a range of tables, charts and DTP layouts from Excel, Word and Adobe's Acrobat Reader. Unlike the first two tests, these documents don't involve any repeated pages, revealing whether print speed is affected by the printer having to process each page image afresh, rather than reproducing a page over and over again.

Finally, we carry out our quality print tests, based on our two standard high-resolution montages - one in monochrome, the other in full colour where applicable - which consist of photographs, shades, gradients and text at a range of sizes.

Scores

Each laser printer receives star ratings out of six for Quality, Speed, Features & Design and Value for Money, plus a final Overall score.

Quality is a subjective rating arrived at by two members of the PC Pro team, who independently assess the output of each printer. We award points to each one based on how sharply it renders small details, how solid and clean black areas are, and how smooth gradients are. For colour printers, we also award marks for the cleanness and accuracy of colours, and how natural photographic content appears.

The speed score reflects each printer's performance in our timed tests, taking into account the time that elapses between the tester clicking Print and the last page that emerges from the printer.

Our rating for Features & Design is calculated by allocating points to a number of different criteria according to the category, as described above. We consider both technical features - such as built-in ethernet, software functions and front-panel controls - and practical benefits, such as warranties and the amount of toner initially included at purchase with each printer.

The Value for Money score represents the overall "bang-per-buck" delivered by each model on test. Naturally, we look at the cost of the printer itself, but we also factor in a calculation of the long-term running costs based on typical usage for that category.

This includes not only toner but the cost of any replacement parts that may eventually wear out, such as the image drum or transfer unit. The overall cost of owning the printer is then weighed against its scores for Features & Design, Speed and Quality to give a Value for Money rating out of six.

Finally, the Overall rating is a strict average of the separate category scores, although it may sometimes appear higher or lower than expected due to rounding.